1. Field of the Invention
The present invention relates to an information recording medium and an information recording and reproducing apparatus that allow recording of information by irradiation with an energy beam. The present invention relates particularly to an information recording medium that realizes a plurality of methods of record mark arrangement on a substrate in a single format and an information recording and reproducing apparatus that realizes the plurality of methods of record mark arrangement.
2. Related Arts
Information recording and reproducing apparatus heretofore well known include the following two types of apparatus: first, the xe2x80x9cDVD Specifications for Rewritable Disc (DVD-RAM) Part 1 PHYSICAL SPECIFICATIONS version 1.0xe2x80x9d (November 1998) (hereinafter referred to as an article 1 (DVD-RAM)) and second, the xe2x80x9cDVD Specifications for Recordable Disc (DVD-R) Part 1 PHYSICAL SPECIFICATIONS version 1.0xe2x80x9d (September 1999) (hereinafter referred to as an article 2 (DVD-R)). DVD-RAM stands for Digital Video Random Access Memory, while DVD-R stands for Digital Video Disc-Recordable.
Sector structure of the article 1 (DVD-RAM) has the following characteristics. A sector of the article 1 (DVD-RAM) has a sector structure with a prepit ID, and a land and a groove forming a recording track meander (wobble). In addition, the sector structure employs an integrated address system in which address information of the sector is disposed at the head of the sector as a prepit. The integrated address is followed by a data field for storing user data; a buffer, a guard, and a VFO field situated before the data field; and a guard and a buffer situated after the data field. Incidentally, a prepit integrated address of DVD-RAM is referred to as a CAPA (Complimentary Allocated Prepit Address).
Sector-structure of the article 2 (DVD-R) has the following characteristics. A groove that forms a recording track of a sector of the article 2 (DVD-R) meanders (wobbles), and land prepits are periodically disposed in a land. According to the method of the article 2, the period of wobbling is accurately detected by a groove wobbling signal and a land prepit detection signal, and then timing in recording is determined with reference to the period of wobbling. As for address information, an address of a single ECC block is distributed over 16 sectors, and is recorded as a prepit in a land prepit of each of the sectors within the single ECC block.
According to the typical methods described above, a self-oscillator corrects the phase of a recording clock by detecting a wobbling signal, or a recording clock is generated by frequency conversion of the wobbling signal. Thus, a recording clock dependent on the wobbling signal is generated in some cases.
According to the conventional information recording media and information recording and reproducing methods, when the method of record mark arrangement in a track is changed, the physical format of the disk is also changed, as in the case of switching between a DVD-R and a DVD-RAM, for example. This makes it difficult to ensure compatibility between pieces of data recorded by a plurality of different methods of record mark arrangement.
Specifically, the DVD-RAM has the CAPA, and therefore user data is not provided in a physically continuous arrangement, while the DVD-R has physically continuous user data, as in the case of the DVD-ROM. Therefore, the different methods of record mark arrangement make it impossible to record information on a DVD-RAM medium by the same procedure as that of the DVD-R, for example, and thus make it difficult to ensure compatibility of recorded data.
Moreover, in the examples described above, since frequency of the wobbling detection signal is considerably lower than that of the recording clock, a slight detection error in the wobbling detection signal results in significant errors in the frequency and phase of the recording clock. When such a recording clock is used in recording, record marks to be written are not necessarily written reliably at specified positions on the disk. Therefore, in the case of DVD-RAM, in order to allow for such errors in the recording clock, length of a recording area within a sector is made somewhat longer than that of a recording area actually used for recording, thereby somewhat decreasing its recording density. In the case of DVD-R, data becomes discontinuous at a linking portion, and thereby a linking loss is caused.
The present invention relates to an information recording medium that realizes a plurality of methods of record mark arrangement on a substrate in a single format and an information recording and reproducing apparatus that realizes the plurality of methods of record mark arrangement, by providing a certain degree of freedom to arrangement and structure of a record mark row within a sector. It is a concept of the present invention to distribute physical addresses (sector address and block address) and thereby set a pre-format. Then, depending on which address is used, sector data structure is modified, thereby making it possible to select an address data detection and a data structure on a disk in a single physical format depending on the purpose.
More specifically, according to a recording and reproducing method of the present invention, a first physical address (a sector address or a block address) is reproduced, and a second physical address (a sector address or a block address) is not reproduced.
Fundamental concepts of main aspects of the present invention will be described in the following.
According to a first aspect of the present invention, the following information recording medium is provided.
An information recording medium for recording information by irradiating a recording track on the recording medium with an energy beam and thereby forming a record mark comprises a sector address included in a unit sector of the recording medium; and a block address which indicates a given address of a given block formed by a plurality of sectors by combining address information included in the individual sectors.
A typical example of an information retaining portion that retains each piece of information forming the above addresses is wobbling or deformation of a track. A recording member based on this typical example may be described as follows. According to a typical aspect of the present invention, there is provided an information recording medium for recording information by irradiating a recording track on the recording medium with an energy beam and thereby forming a record mark, wherein the recording track has wobbling or deformation with a predetermined period, the wobbling or the deformation of the recording track within a unit sector being divided in a temporal direction into a plurality of portions; at least one of the plurality of divided portions of the wobbling or the deformation of the recording track within the unit sector includes address information of a block address; and at least another portion of the plurality of divided portions of the wobbling or the deformation of the recording track within the unit sector includes address information of a sector address.
The wobbling or the deformation of a track is used as an example for later description of concrete structure of a recording medium according to the present invention. However, it is to be understood that the essence of the present invention is not limited to the concrete structure.
The wobbling or the deformation of a track on a recording medium preforms information for addressing by a block unit rather than by a sector unit and information on an address to be recorded in each sector. A format of the former for addressing by a block unit as described above is generally referred to as distributed addressing, because the address is distributed over the block as a unit and thus recorded. A format of the latter is generally referred to as integrated addressing, because address information is recorded in each sector, mostly at the head of the sector. Either of the plurality of addressing methods mentioned above is selected, and user information is recorded on the recording medium according to the format of first recording information and the format of second recording information. It is to be understood that the address information mentioned above includes information on sector structure of the sector. User information to be recorded includes information that specifies which of the addressing methods described above should be used. More specifically, user information includes information indicating that address information is to be extracted from an SAF area or to be extracted from an HAF area in each sector, as will be described later.
Such selection is made typically for the following reasons. The format for addressing by a block unit is suitable as a recording format for current DVD-RW mode, because redundancy of address information recording is at a high level, and therefore few errors will occur in address information. On the other hand, the format in which an address is recorded in each sector is suitable as a recording format for current DVD-RAM mode, because its rate of occurrence of address information errors is not better than the former, but its information recording density per unit recording length is higher.
Thus, with the recording medium according to the present invention, it is possible to preform fundamental address information in wobbling or deformation of a recording track, and to select a recording format suitable for information to be recorded by the user from the recording formats for the plurality of modes mentioned above according to characteristics of the information to be recorded.
According to a second aspect of the present invention, the following information recording and reproducing apparatus is provided.
An information recording and reproducing apparatus comprises a signal detecting circuit for converting a period of a configuration of each record retaining portion on a recording track into an electric signal, the recording track being provided in advance on a recording medium and including the record retaining portion having the configuration with the predetermined period; a block address detecting circuit for detecting a block address by converting a period of the electric signal obtained by the signal detecting circuit; a sector address detecting circuit for detecting a sector address by converting the period of the electric signal obtained by the signal detecting circuit; and an address switching circuit for switching between output of the block address detecting circuit and output of the sector address detecting circuit and thereby transmitting a resulting output to a controller.